Drawing-board.



PATENTED SEPT. 6, 1904.

A. KR AH. DRAWING BOARD.

APPLICATION FILED MAR. 10, 1904.

N0 MODEL.

We? 60%? ea"- UNITED STATES Patented September 6, 1904.

' ATENT CFFIQE.

DRAWING-BOARD.

SPECIFICATIONforming part of Letters Patent No. 769,441, dated September 6, 1904.

- Application filed March 10, 1904. Serial No. 197,550. No modelfi T0 (LZZ whom, it nuty concern:

Be it known that I, ALEXIS KRAH, a citizen of the United States, and a resident of New Haven, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Drawing-Boards, of which the following is a specification.

My invention relates to an improvement in drawing-board attachments, and has particularly for its object to provide means for readily attaching and detaching one edge of a sheet of drawing.

A further object is to provide a device in which the use of thumb-tacks is obviated along the bottom edge of the sheet of drawing.

A practical embodiment of my invention is represented in the accompanying drawings, in which Figure 1 represents in top plan, partially broken away, a portion of a drawing-board with my improved attachment applied thereto, a sheet of drawing-paper being shown clamped in position thereon. Fig. 2- is an end view of the same. Fig. 3 is a partial side view. Fig. A is a vertical section in the plane of the line A A of Fig. 1; and Fig. 5 is a partial top plan view of a drawing-board with my improved attachment applied thereto, the device being shown in its released position.

The drawing-board is herein represented by 1, the sheet of drawing by 2, and the thumbtacks, which secure the top of the sheet to the drawing-board, by e. The bottom of the sheet is attached to and released from the drawing-board by the following device: A block 41 extends transversely across the bottom of the drawing-board 1, the face of the block being flush with the face of the board 1. This block is secured to the board by two strips 5 and 6, which extend from the back of the block A underneath the board 1 and are there secured by suitable screws 7 or other fastening devices. This block A is provided with a tapered undercut shallow groove 8, which groove extends transversely across the drawing-board. The inner wall 9 of this groove is perpendicular to the sides of the drawing-board, and the outer wall 10 is necessarily at a slight angle with respect thereto. A wedge 11 is fitted to slide in the undercut groove 8, the inner and outer sides 12 and 13 of the wedge being parallel with the inner and outer walls 9 and 10 of the groove. The side 13 ot' the wedge is held at all times in engagement with the wall 10 of the groove by pinand-slot connections 1% 15, the slots 15 being parallel with the wall 10. This will cause the side 12 of the wedge to approach and recede from the wall 9 of the groove as the wedge is moved laterally. The block 4: may have holes 16 communicating with the slots 15 for the purpose of driving the pins 14: out of engagement with the said slots if it should be desired to do so.

The means which I have shown for sliding the wedge 11 is constructed, arranged, and operated as follows: A rotary cam is mounted in the bloelvinear the wide end of the groove s, the top 17 of which cam is provided with a flange 18, which is countersunk, so as to leave the top of the cam flush with the bottom of the groove. The body of the cam is denoted by 19 and projects through the back of the block 1 and is there provided with a suitable handle 20. The top 17 of the cam is provided with an eccentric stud or roller 21, which is located in an elongated slot 22, extended transversely of the wedge 11, but parallel with the sides of the drawing-board 1. This roller-and-slot connection between the cam and wedge is such that when the cam is turned in one direction the wedge will be opened and when turned in the other direction the wedge will be closed.

In praetice,after the lower edge of the drawing-board sheet 2 is inserted between the side 12 of the wedge and the wall 9 of the groove the wedge is then closed, serving to clamp the sheet firmly to the board. The sheet is then bent over and pressed down along its portion adjacent to the wedge to form a sharp bend in the sheet. The sheet is then smoothed out upon the drawing-board and the edge of the sheet is secured to the drawing-board by the thumlrtaclts 3. When it is desired to release the bottom edge of the sheet 2-as,'t'0r instance, when the sheet is to be left for some time where it will be subject to ditl'erentconditions of temperature and moisture-the cam 19 is turned in a direction to slide the wedge in a direction permitting the folded-over portion of the sheet 2 to be removed from its position. It Will be seen that the sheet may be readily replaced and clamped When so desired.

While I have shown the drawing-board 1 in the present instance as extended by the use of the block A, it is to be understood that the shallow groove 8 may he made in the face of the board as Well as in a separate attachment.

It is evident that slight changes might be resorted to in the construction, form, and arrangement of the several parts Without departing from the spirit and scope of my invention. Hence Ido not Wish to limit myself strictly to the structure herein set forth; but

What I claim as my invention is 1. A drawing-board and means for removably securing a drawing-sheet along one edge thereto, comprising a tapered groove, a sliding Wedge Within the groove and guides for causing one side of the Wedge to approach and recede from one Wall of the groove to clamp and release the sheet.

2. A drawing-board and means for removably securing'a drawing-sheet along one edge thereto, comprising a tapered groove,asliding Wedge therein and a cam for operating the Wedge to cause one side thereof to approach groove in the upper face of the block, a laterally-sliding Wedge therein and means for causing one side of the Wedge to approach and recede from one Wall of the groove to clamp and release one edge of a drawingsheet.

In testimony that I claim the foregoing as my invention I have signed my name, in presence of tWo Witnesses, this 4th day of March, 1904:.

ALEXIS KRAH.

Witnesses:

JOHN B. KENNEDY, CARL W. JOHNSON. 

